*{
  box-sizing:border-box;
}
.clear-fix:after{
  content:"";
  display:block;
  clear:both
}
.tab-bar{
  position:fixed;
  bottom:0;
  width:100%;
}
.tab-item{
  width:20%;
  height:57px;
  border:2px solid black;
  text-align:center;
  line-height:57px;
  float:left;
  
}
